This invention relates to an emergency brake for presses or the like and more particularly to an improved press emergency brake.
As is well known, most mechanical presses employ a clutch and brake arrangement which permits the press ram to move through a cycle of operation from a home position through a striking or operative position and back to the home position. Normally, the brake and clutch mechanism is operated so that the brake is released when the drive clutch is engaged and the brake is re-engaged and the clutch disengaged when the ram returns back to its home position. In order to provide additional safety, it has been proposed to incorporate an emergency brake for the ram which has the purpose of preventing accidental movement of the ram in the event of failure of the conventional press clutch and braking mechanism. For the most part, these emergency brakes incorporate positive detent elements which are engaged with each other when the press ram is in its home position. The disadvantage of this type of locking mechanism is that it depends upon the detent element being accurately aligned at the time the emergency brake is actuated. If this accurate alignment is not insured, the emergency brake will be inoperative. Another disadvantage of this type of system is that it does not truly provide an independent emergency brake that is only operative to stop the ram movement in the event of malfunction.
It is, therefore, a principle object of this invention to provide an improved emergency brake for presses or the like.
It is another object of this invention to provide an emergency brake for presses that does not depend upon accurate location of the braking elements to become effective and further one in which the braking elements may be moved to their braking position and retained in that position during a substantial part of the press operation cycle so as to insure safety braking in the event of failure.